Samsung started the Galaxy ‘Active’ smartphone line in the year 2013 with the introduction of the Galaxy S4 Active. The S4 Active was similar to the Galaxy S4 in most respects, except for a much more rugged body with IP67 certification for dust and water resistance. Although the device was more of a niche offering and wasn’t offered in a number of markets, it is good to see that Samsung is offering the same level of software support for the smartphone as the regular flagship Galaxy S4. The Android 5.0 Lollipop for the smartphone has begun rolling out, although currently the update is only seeding to owners of the AT&T Galaxy S4 Active variant SGH-i547. The Lollipop update for the GT-I9295 International variant is still awaited. While you wait for the Lollipop rollout to begin for the International variant, you do have the option of trying out the Unofficial CM 12.1 ROM available on XDA, based on the latest Android Lollipop 5.1.1 version.

The Unofficial CM 12.1 builds for the Samsung Galaxy S4 Active have been developed by XDA senior member spegelius. Currently the Android 5.1.1 Lollipop based CM 12.1 builds are not very stable and there are a few major bugs. Mainly the bugs have to do with the camera functionality. Whenever you switch on the HDR feature or turn the flash off, the camera app might freeze. With the default camera, you will need touch focus to take a picture. However, this issue may not be present when using a third party camera app such as Google camera. 720p HD video recording quality is said to be quite unimpressive as well. Apart from these camera related bugs, there are also some Bluetooth incompatibilities with certain devices and some have reported audio problems when playing music. So if these issues bother you, we suggest you wait for more stable CM 12.1 builds to become available before you flash it on your Galaxy S4 Active. However, if you can live with these issues, the ROM can be used as a daily driver as all of the other major functions are working fine currently. The Unofficial CM 12.1 ROM also includes a few additional features over the Official CM 12 Nightly such as f2fs support and dualboot. As we mentioned earlier, this ROM is meant only for the GT-I9295 variant of the Galaxy S4 Active, so do not flash it on your device if you own the AT&T Galaxy S4 Active.

In this tutorial we are going to walk you through the steps involved in flashing this Unofficial CM 12.1 Android 5.1 Lollipop custom ROM on your Samsung Galaxy S4 Active. We suggest that you follow the guide carefully and do not skip any step or use your own judgment to do anything differently. If you make a mistake during the installation process, you may end up bricking your Samsung Galaxy S4 Active.

Before we get to the ROM installation process, we will need to make sure that your Samsung Galaxy S4 Active is ready for the installation. The first thing that you will need to do before heading to the installation process is to make sure that you have a backup of all your important data ready. You can do backup your personal data, contacts, SMS, apps and app data with the help of a third party backup and restore application from the Google Play Store. Some of the popular backup and restore apps on the Google Play Store are Titanium Backup, Helium and MyBackup. Alternatively, you could also back up your data to your computer using the any Android backup software available for PC. Along with the backup of your personal data, you should also take a Nandroid backup of your current ROM so you can revert to it in case you aren’t too happy with this Unofficial CM 12.1 Android Lollipop ROM. If you haven’t taken a Nandroid backup yet and are clueless, please head to our tutorial on taking a Nandroid backup at this link.

To be able to install the Unofficial CM 12.1 Android 5.1 Lollipop ROM on your device you will need to have an unlocked bootloader. Like any other AOSP based ROM, this ROM also requires that your device’s bootloader be unlocked. So you will need to unlock the bootloader of your Samsung Galaxy S4 Active before you are able to install the ROM. However, be warned that unlocking the bootloader will void the warranty on your device. So make sure you keep this in mind before deciding whether or not you want to proceed with the unlocking of your Samsung Galaxy S4 Active bootloader. You will also need to have a custom recovery installed on your device as the ROM needs to be flashed via custom recovery. Some of the popular custom recovery options are CWM, TWRP, and PhilZ recovery. Make sure you download and install the latest version of any recovery that you may choose. If you have older version of recovery installed on your device, we suggest you install the updated version. Root access is required too, so we recommend that you root your Samsung Galaxy S4 Active before you proceed to install the ROM on it.

A very important thing that you should keep in mind each time you install a new custom ROM on your device is to ensure that your device has at least 60% battery charge remaining. In case the battery of your Galaxy S4 Active runs out during the ROM installation process, it will end up getting bricked. In case you need to take your device for service to get it fixed, you will need to pay for the expenses as the warranty is void after unlocking the bootloader. So we suggest you charge your Galaxy S4 Active battery before installing the ROM, in case there is less than 60% battery charge remaining.

Finally, you need to make sure that the USB Debugging option is checked under Developer options on your Samsung Galaxy S4 Active. You will need to go to Settings – Developer Options – USB Debugging and then make sure that the USB Debugging option has been checked. If it is not checked already, make sure you check this option.

Now that all the prerequisites for installation have been taken care of, we now proceed to the ROM installation process.

The very first thing that you will need to do in order to proceed with installing the Unofficial CM 12.1 Android 5.1.1 Lollipop ROM on your Samsung Galaxy S4 Active is to download the ROM ZIP file from this link and save it to your computer. You will need to download the GAPPS (Google Apps) ZIP file along with the ROM ZIP file as this ROM does not come with any Google apps or services by default, just like any other AOSP based ROM. GAPPS for Android 5.1 Lollipop can be downloaded from this link.

Once both the above files are downloaded to your computer, connect your Samsung Galaxy S4 Active to the computer using the USB cable and transfer both the files to the internal storage of your device. Make sure that you transfer the files to the internal storage and not the external SD card as you will not be able to flash the files if you accidentally move them to the external SD card. We also recommend you transfer the files to the root directory of your device in order to make it easier for you to find the files when you have to choose them via recovery in a later step.

After both files have been transferred successfully to the internal storage of your device, disconnect your Samsung Galaxy S4 Active from the computer. Now turn it off and enter recovery mode.

In recovery, tap on the ‘wipe data factory reset’ option to perform a factory reset. Once that is done, tap on the advanced options to wipe the cache, dalvik cache, data and system partitions. This is very important as not wiping everything could lead to some issues post flashing. A ‘clean’ install by wiping everything eliminates the chances of facing any such issues. In future when you wish to upgrade to a newer version of this or any other ROM you may have installed on your device, you will only need to wipe the cache and dalvik cache.

After wiping everything, return to the main recovery menu and tap on the ‘Install zip from SD card’ option and choose the Unofficial CM 12.1 ROM ZIP file that you had transferred to the internal storage of your device earlier. Flash the file to install the ROM on your device.

Now proceed to flash the GAPPS ZIP file in the same way to install GAPPS on your device.

After the GAPPS ZIP file has been flashed, tap on ‘reboot system now’ to reboot your device.

That’s it. You should now have the Android 5.1.1 Lollipop Unofficial CM 12.1 ROM installed on your Samsung Galaxy S4 Active. The first boot will take much longer than usual, so do not panic if your device takes around five minutes or longer to boot to the homescreen. It is perfectly normal.

If you wish to report any bugs that you may find with this ROM or for any other discussion related to the ROM, make sure you follow the official ROM thread on XDA at this link.